Technical Abstract:
Forage quality of grazed swards is closely associated with the contribution and quality of morphological components. We determined leaf and stem fraction dry matter and forage quality trends for temperate perennial grasses at two Wisconsin locations. After reaching 15 to 20 cm height, primary spring, summer, and fall growth of bluegrass, meadow fescue, orchardgrass, quackgrass, reed canarygrass, ryegrass, smooth bromegrass, tall fescue, soft-leaf tall fescue, and timothy was clipped to a 10-cm stubble every 5 d to 30 d maturity. Rate of stem accumulation during the spring was greater at the northern location than at the southern location for most species. Ryegrass and orchardgrass produced the least stem fraction and reed canarygrass produced the most. Rate of leaf accumulation was greater at the northern location during the spring and summer, but was greater during the fall at the southern location. At the most immature stage, neutral detergent fiber digestibility (NDFD) was greater in the spring (750 to 950 gm/kg) compared to the summer (600 to 700 gm/kg), but declined more rapidly during the spring to a minimum of 550 to 650 gm/kg. Appropriate grazing management is most critical for quackgrass, reed canarygrass, smooth bromegrass, and tall fescue, which exhibited the most rapid rate of decline in leaf NDFD with maturity.